No, your cell phone isn’t trying to kill you.

Maybe

By Matt Simon

The tin foil hat, while fashionable, is an ineffective way of keeping the government’s radio waves from infiltrating and manipulating your mind. In fact, the hat may boost certain radio frequencies, which is OK because there’s no such thing as mind-controlling waves anyway.

But you might have heard that you should really worry about the radio waves that spew out of your cellphone—that they can cause brain cancer. 

That too, I’m happy to report, probably isn’t true. At least, no one has yet proven a solid link between cancer and phone use. But that’s where things get complicated.

First off, radio waves are indeed a form of radiation. 

But they’re relatively low-frequency waves, and are therefore low energy. High frequency, high energy waves like X-rays can damage your DNA—radio waves cannot. (What radio waves can do, though, is heat up your flesh. But again, the energy is too weak to do any damage to your ear, much less your brain.)

Still, beginning in the 1950s, researchers began speculating that radio waves might cause cancer. “But that was just speculation,” says Otis Brawley, chief medical officer of the American Cancer Society. “We really still don’t have definitive answers as to whether they do cause cancer.”

The first real studies looking at the link between cellphones and cancer asked patients with brain tumors which ear they typically held their phone on. And sure enough, three quarters of them favored the side of the head where their tumors developed. 

Correlation, right? Well, not necessarily. First of all, the respondents had a 50 percent chance of choosing a given side, so 75 percent of them guessing correctly could be a fluke. That, and there was a huge potential for bias here. 

“The people who are answering the question, they know which side of the brain the tumor is,” Brawley says, “so they might actually answer the question to favor that side.”

Really, the problem is ethics. I’ll rephrase that: Ethics are lovely, in science or otherwise, but they limit what scientists can and can’t do experimentally. They can’t just sit people in the lab and bombard them with known carcinogens to see what happens. 

The same goes for radio waves: If this particular kind of radiation did turn out to be linked to cancer, and you’d fired incredible amounts of radio waves at your patients’ brains, you’d feel like a bit of a horse’s patootie.

Researchers, then, have to work instead with model organisms like mice and rats. And that’s exactly what they did last year in a study you likely heard about because the media got a bit … carried away with it (headlines e.g. “‘Game-Changing’ Study Links Cellphone Radiation to Cancer”). The scientists did find that rats exposed to radio waves developed tumors, but like with the human brain tumor study, this study came with some serious caveats.

For one, rats may be a decent stand-in for humans, but they’re not humans. Their tissues may react to radio waves differently. And then there’s the dosage: The researchers hit their tiny subjects with up to seven times the radiation a human would get with a cellphone. We’re talking exposures of nine hours a day for months straight. And in the end, the research wasn’t peer reviewed—a big tick in the “let’s carefully consider this study” column.

So with frustratingly scant data on the link between cellphones and cancer, health organizations have to carefully word their positions: Phones might cause cancer because evidence either proving or disproving a link just isn’t there. The UN’s International Agency for Research on Cancer, for instance, has declared cellphone use “possibly carcinogenic to humans.”

“A lot of people were really concerned when they heard the United Nations cancer agency has declared that cellphones might cause cancer,” says Brawley. “But when you realize that lipstick, pickles, and styrofoam are on that list, it puts it into a different perspective.” None of those things are necessarily super high-risk—the IPRC designation just leaves open the possibility that some carcinogenicity exists.

In other words, a dearth of data means that no one would conclude right now that that cellphones cause cancer. “I think it’s an unsettled question, it’s a legitimate question,” Brawley says. “I believe the answer is no.” 

After all, he notes, brain tumor rates haven’t increased over the last 40 years. “However, none of us can tell you what the 30 or 40 year experience of people using cellphones will be,” he adds, “because we haven’t had cellphones that long.”

So unless you find that tin foil hat to be irresistibly fashionable, you might want to consider parting ways. Or keep the hat and just text more. Who am I to jam your style?